Package for tobacco products



Jan. 31, 1967 J. sTALEY PACKAGE FOR TOBACCO PRODUCTS Filed Dec. ll, 1964United States Patent O 3,301,468 PACKAGE FOR TOBACCO PRODUCTS JohnStaley, Richmond, Va., assignor to Philip Morris Incorporated, New York,N.Y., a corporation of Virginia Filed Dec. 11, 1964, Ser. No. 417,756 6Claims. (Cl. 229-87) This invention relates to an improved package fortobacco products and the like and to a method for making the same. Moreparticularly, the present invention relates to an improved cigarettepackage and method of making the same.

The invention relates most particularly to containers which are made upof a plurality of layers of material, one of said layers bein-g a layerof material, such as aluminum foil, which is substantially impervious tothe passage therethrough of water vapor and another of said layers beinga librous or hydrophilic material, such las paper, which readily picksup moisture from its surrounding environment.

While paper can provide the necessary stiiness and feel for a tobaccoproduct package, it obviously does not have the barrier properties ofsuch materials as aluminum or tin foil. On the other hand, aluminum ortin foil, alone, while providing a goo-d moisture barrier, do not havesufficient stiffness in the thicknesses which are economically feasiblefor packaging operations.

A laminate or -its equivalent made of a water-impervious material, suchas aluminum foil or the like, and a hydrophilic material, such as paperor the like, provides one of the most economical and most desirablematerials for use in the packaging of tobacco products. Thus, a commontype of package for tobacco products, and particularly cigarettes, is apackage which ismade with a laminate which comprises paper and aluminumfoil held together by la suitable adhesive and coated on one or bothsides, when desired, with a thermoplastic coating. Such laminatedpackages, which are presently being used com- -merically in thecigarette industry, are generally folded without being heat-sealed.While it might appear that such a package would, due to the presence ofthe aluminum foil, form an eiective moisture barrier to prevent undueloss or gain of moisture from the cigarettes contained therein, this hasnot been found to be true. Such packages have been found to be inadquateto maintain cigarettes at the proper degree of moisture for anysubstantial period of time.

Even when such a laminated package is sealed along its edges by means ofheating the thermoplastic coating to a suiicient degree to melt it andpermit it to harden to form a seal along the edges of the package, theystill fail to form an effective moisture barrier and commercial,cigarette packages do not have their edges sealed.

In an attempt to overcome the problem'of undesirable moisture loss orgain, when a paper-foil laminate is employed4 as the packaging material,a separate moisture barrier has commonly been employed with suchlaminated packages.

The major moisture barrier now in use in the tobacco `industry forpackaged cigarettes is the cellophane overwrap. This overwrap isactually a separate package which is employed over the laminatedpackage. However, the barrier properties of cellophane are not adequatefor properly maintaining the .original moisture and oxygen in thecontents of the package. Over a period of time, substantial amounts ofthe water vapor, oxygen and ilavorful aromatic vapors can leak throughboth the inner laminate package and the outer cellophane package.

Coatings made of water impermeable materials, such as wax, `have beenfound to be of some help in increasing the water vapor barrierproperties of the package, but solvent action which occurs duringsealing operations often removes the coating land exposes thehydrophilic cellophane layer.

The present invention overcomes the disadvantages of the prior art andprovides an improved package wherein the water vapor transmission rate(WVTR) of the pack- Iage is greatly reduced and the moisture content ofthe package product is substantially retained over long periods of time.In addition, the present invention provides a package wherein the lossof volatile materials and flavors from the tobacco product are greatlyreduced. The present invention also furnishes a means for controllingthe diffusion rate of oxygen into the package whereby spoilage due tothe -action of anaerobic bacteria can be prevented.

I have discovered that, in packages containing fibrous layers, the brouslayers function as wicks to conduct moisture vapor and other vapors orgases from the inside of the package to the outside .or vice versa.

No matter how many layers are involved in a laminated material when oneof the layers -is a hydrophilic or librous material, such as paper, theibrous material provides a wicking elfect, conducting moisture either inor out of the package, even though .only the edges of the brous materialare exposed to both the interior and the exterior of the package.

In accordance with the present invention, an improved package element isprovided comprising a plurality of layers, including at least onelibrous or hydrophilic layer and at least one water-impervious layer,said plurality Aof layers being folded and joined by means of aplurality of seams to form a package having an interior atmosphere, saidpackage having no brous layers which connect the interior atmosphere ofthe package element with the atmosphere which is exterior to the packageelement.

Briefly, the package element of the present invention can be made byfolding under one surface of each seam or joining, so that there isalways water vapor impervious layer-to-water vapor impervious layercontact along each seam of the package.

The water vapor impervious layer-to-water vapor impervious layercontact, for example, foil-to-foil contact, along each seam, may be oneither the inside or the outside of the package element. Furthermore,the package element may be constructed of a plurality of distinct andunjoined layers or may be constructed of a laminate or composite oflayers which are joined together by adhesives or resins and coated bywaxes, resins and the like.

Furthermore, the package element may -be employed in conjunction Withother packaging elements, suchas a cellophane overwrap; a combination ofa paper overwrap,

which may fbe suitably printed in color with a 'brand name and othersuitable printed matter, and an outermost cellophane overwrap; an outercardboard box or an outer plastic case or box.

The present invention is particularly applicable to cigarette packagesand is equally effective with single component packs, wherein a laminateof paper and aluminum foil forms the entire wrap; with soft packs,wherein a paper wrap and a cellophane outer wrap are employed with alaminate of paper and foil; withI cardboard boxes or plastic casescontaining a laminate of foil and paper, and with many other packagingapplications.

While the invention is particularly applicable tocigarette packages, itis equally effective for use in tobacco pouches and containers for othermaterials. It may also be employed in conjunction with outer cellophanewrappers, iptop boxes, plastic cases and the like.

An outstanding advantage of the present invention resides in the rfactthat with a few simple additional folds in the blank, a tobacco packagecan be made which is outstandingly superior to any package which hasheretofore been made. Thus, with a minimum of additional adjustment andchange in packaging equip-ment, conve-ntional packaging materials can beemployed to much greater advantage to provide packages which result inbenefits heretofore unachievable with the materials which are employed.Furthermore, the package can be opened in a conventional manner and theonly distinction between the appearance and function of the presentpackage from that of conventional cigarette packages is the fact thatthe ilaps are double folded to provide foil-to-foil or similarimpervious surface-to-impervious surface contact at all edges and toensure that no hydrophilic materials are exposed to both the interiorand exterior of the package either on their surface or along theiredges.

While the package element can |be sealed along all its edges, aparticularly preferredI form of the present invention resides in apackage element for tobacco products and the like which not onlyprevents any significant amount of undesirable transfer of moisturevapor in or out of the package element and which prevents anysignificant loss of desirable flavors and aromas, but which also permitsthe passage of oxygen to the interior of the package element. Iaccomplish this by leaving at least a portion of one foil-to-foil orsimilar seam of the package element, after it has been 'formed into theshape of a container, unsealed Ibut by so folding one of the edges ofsaid seam that the resulting free passage or adhesiveless closure fromthe interior of the package element to the exterior of the packageelement is at least 50 times and preferably 100 times as long, in thelength or direction going to or from t-he interior of the package to orfrom the exterior of the package, as the distance or height between thetwo water vapor impervious surfaces which form the unsealed seam. Theentire package element may -be made in this manner, without the use ofadhesives. Alternatively, an adhesive can be used intermittently alongany or all seams of the package ele-ment or all but one or a portion ofone of the seams may be sealed. However, there should 'be atleast aboutone-quarter inch `and preferably at least about one inch of seam whichhas the relationship of height to length described above and which isnot held together by adhesive. Such a length of seam can be descri'bedas an adhesiveless closure. All other seams in the package elementshould have a foil-tofoil or similar contact of at least about 1/16thinch and, any seam in the package element which does not have theabove-described relationship of height to length, should be sealed witha suitable hydrophobic adhesive.

The adhesiveless closure allows the package to breathe; that is, itallows oxygen to diffuse into the pack and carbo-r1 dioxide to diffuseout of it. It is well known in the tobacco industry that anaerobicaction can cause the formation of undesirable aromas within completelysealed or substantially completely sealed packages, when the interioratmosphere of the package falls below a certain oxygen content.Therefore, control of oxygen content is desirable. The adhesivelessclosure of the present invention offers excellent protection against theloss or gain of moisture and still allows the passage of oxygen andcanbon dioxide to the interior of the package. The length of theunsealed' seam controls the breathing and the passage through the seamhas essentially zero permeability if, as set forth above, the length ofthe path in the direction of diffusion is greater than approximately 50times the width of the gap.

The wickless packages of the present invention have been proven to bemany times more effective in reducing moisture migration in packagedcigarettes than the standard packages overwrapped with cellophane. Andthe combination of a wickless package with an adhesiveless closure of:the type described above has provided even greater overall advantages.

Thus, packages of the present invention can be employed to provide anopening for the exchange 0f oxygen and carbon dioxide between thecontents of the package and the atmosphere, the exchange taking placeWithout any significant change in the moisture content of tobacco. Theinvention thereby provides for a package which can be stored for longperiods of time without any undesirable moisture changes and without anyundesirable changes due to the absence of oxygen in the package.

The present invention overcomes a long standing problem in the art: apackage which was stored for a long period of time with a barrier whichwas sufficient to prevent moisture loss had a resulting depletion of itsoxygen content, whereby the tobacco was subject to attack by anaerobicbacteria. If, on the other hand, the package was stored for a longperiod of time without such a moisture barrier, in order to provide forpassage through the package of oxygen, moisture would be lost or, in theevent of an atmosphere that was excessively moist, the :tobacco wouldpick up excessive moisture, in short, the moisture content of thetobacco would be changed undesirably. Such problems are eliminated bythe present preferred method land process.

Water vapor impervious materials which may be employed in accordancewith the present invention include aluminum foil, tin foil, lead foil,polyethylene, polypropylene, wax and the like. Calendered plasticizedvinyl resin sheets may also be employed. A vinyl resin sheet cancomprise polymerized vinyl chloride or copolymers of vinyl chloride withvinyl esters, vinyl acetate and vinylidene chloride. These materials maybe employed as sheets or as coatings and, when employed as sheets, maybe employed as lamina, adhered to other lamina by means of suitableadhesives, or may be used with other lamina without being adheredthereto.

Fibrous or hydrophilic materials which may be employed in accordancewith the present invention include such materials as paper, for example,glassine, kraft paper, sulte paper and the like, thin cardboard yandsimilar materials.

vThe water vapor impervious material and the fibrous material, when bothare in sheet form, may be joined together by a suitable adhesive whichmay be any of the well-known types that may or may not be applied with asolvent or, on the other hand, may include a thermoplastic type ofadhesive. Various adhesives are known for bonding paper to metal, forexample, casein glues and silicate cements.

The outer surface of either or both layers of the resulting laminate maythen be coated either completely or partially, along the areas to bejoined together, with a thermoplastic material or may be bonded toathermoplastic sheet, said thermoplastic coating or sheet being free fromtackiness at normal atmospheric temperatures and possessing suchthermoplastic cohesive properties that it can be used to selectivelybond the edges of the package together due to the application of heatand pressure.

` The specific nature of the thermoplastic sheets or coatings which maybe employed may vary somewhat in compositions, although such materialshould, in any event, have the physical characteristics mentioned above.Suitable materials include polyethylene, polypropylene, rubberhydrochloride (commercially available as Pliofilm), chlorinated rubber(commercially known as Pliolite), alkyd resins, phenol formaldehyderesins, vinyl acetate polymers, polyvinyl chloride homopolymersandicopolymers, vinylidene chloride polymers, for example, Saran,cellulose derivatives as cellulose esters and cellulose ethers, forexample, cellulose acetate, when properly plasti-cized with selectedplasticizers in suitable amounts, c0- polymers of butadiene and styrene,polystyrenes, nitrocellulose coatings properly plasticized with selectedplasticizers so as to be suitably thermoplastic, inert protein polymerswhen properly formulated and plasticized, and other generally similarcompositions of thermoplastic materials which are free from tackiness atnormal atmospheric temperatures but have such thermoplastic cohesiveproperties that they may be selectively bonded together permanently orsupercially by the application of heat and pressure.

The resulting laminate may then be employed with the water vaporimpervious material on either the inside or the outside of the package,so long as the blank from which the laminate is made is folded andsealed in accordance with my invention.

The use of a thermoplastic outer layer or coating is preferred, since itcan be readily employed to heat seal the edges of the package. However,when no thermoplastic materials is used as an outer coating or surfacelayer, a water impervious resin or adhesive may be applied to the edgesof the package to seal the edges in accordance with the presentteachings.

In the preferred embodiment of the invention, wherein an adhesivelessclosure is employed, i.e., wherein at least one seam is left partiallyunsealed and wherein all seams may be unsealed, a coating ofthermoplastic materials, such as polyvinyl acetate, on the water vaporimpervious layer, such as foil, which is preferably relatively thin, forexample, from 0.05 to 0.8 mil in thickness, does not change the resultswhich are obtained from a foil-to-foil or similar relationship,Iprovided the coating itself is not hydrophilic, i.e., does not serve asa wick, and provided the proper ratio of length to width of the opening,as set forth earlier in this specification, is maintained. Such coatedfoil-to-coated foil or similar contact can, for the purposes of thisapplication, be considered foil-to-foil contact.

In the case where there has been heat sealing of two coatedfoil-to-coated foil surfaces, by means of a thermoplastic coating, itcan be considered :that there is essentially a foil-to-foil contactestablished through the heat seal.

For a fuller understanding of the nature and objects of this invention,reference should be had to the accompanying drawings, in which:

FIG. l is a plan view of a blank from which the package element of thepresent invention can be made.

FIG. 2 is za perspective view of the package element;

FIG. 3 is a front view of the package element;

FIG. 4 is ya sectional view of the paclcage of FIG. 3, taken along theline 4--4 except that the thickness of the lamina is shown exaggerated;and

FIG. 5 is an enlargement of an upper portion of FIG. 4.

As shown in FIGS. l5, |and particularly in FIG. 1, laminated blank 1which comprises an inner or lower lamina 1a made of fibrous orhydrophilic material, such as paper, and .an outer or upper lamina 1b,made of |a vapor barrier, such as aluminum foil, which is bonded totheinner lamina by a suitable adhesive is rectangular in shape. The upperlamina may be coated completely on its face with a thermoplastic resin,such as polyvinyl acetate. Blank 1 comprises longitudinal score lines2-7, lateral score lines 8-10 and 10 `and angular score lines 11-16 Iand11-16. Score lines 4, 8, 5 and 9 define the front panel B. Score lines3, 8, 4 `and 9 and 5, 8, 6 and 9 define, respectively, the side panels Aand C. Score lines 2, 8, 3 and 9 and 6, 8, 7 and 9 dene, respectively,the back panel section D and the back panel section E. The top folds ofthe package .are formed by that portion of the blank bounded by edges20, 21 and 22 and score line 8. The bottom folds of the package areformed Iby that portion of the yblank bounded by 'edges'20, 2.1 and 22and score line 9.

To form t-he novel container of the present invention from blank 1, sidepanel A is folded back along score line 4 until it is at :an .angle of90 from the plane of front panel B. Side panel C is similarly foldedback,

, .acetate coating `and is heat sealed `at the seam to melt along scoreline 5 until it is at an angle -of 90 with the plane of front panel B.Back panel section D, which is defined by score lines 2, 8, 3 yand 9 andis folded back, along score line 3l to form an angle of 90 with theplane of side panel A. Back panel section E, which is formed by scorelines 6, 8, 7 land 9, is folded along score line 6 to form an angle of90 with the plane of side panel C. Flap F, which is formed by score line7 and edges 21', 22 and 21, is folded inwardly through an angle of 180.along score line 7 and is then posit-ioned so that its upper surface,in this case aluminum foil, then forms a lower surface which is definedby score lines 7, 8 and 9 and edge 22, is positioned over edge area Gwhich is bounded by score lines 8, 2 Iand 9 and edge 20 which isadjacent rear panel section D. In this manner, a foil-to-foil seam ismade which can be sealed by heat sealing the thermoplastic coating, ifused, or by applying a suitable :adhesive .and sealing the two seamstogether. Preferably, Where a water impervious seal is desired, the foilis completely coated with a polyvinyl the polyvinyl Iacetate and permitit to cool to form the seal along said seam.

Panel H, which is bounded by score lines 3, 9 and 4 'and edge 21 isfolded inwardly to form an angle of 90 with panel A along score line 9.When panel H is folded inwardly, it holds t-riangularly shaped panel J,which is bounded 'by score lines 3 and 11 and edge 21 and triangularlyshaped panel K, which is bounded by score lines 4 .and 12 fand edge 21outwardly so that they fold, respectively, along score lines 11 and 13at an angle of 180 with, respectively, panel P' which is bounded byscore lines 2, 9 and 11 and edge 21 and panel Q which is bounded byscore lines 9, 13, 10 and 12. When panel L, which is bounded by scorelines S, 9 and 6 and edge 21, is folded inwardly, it holds triangularlyshaped panel N, which is bounded by score lines 6 and 14 and edge 21,and triangular-ly shaped panel M, which is bounded by score lines 5 and13 and edge 21, outwardly so that they fold, respectively, along scorelines 14 and 13 at .an :angle of 180 with respectively, panel R, whichis bounded by score lines 9, 7 and 14 and edge 21 and panel Q, which isbounded by score lines 9, 13, 10 and 12.

The flap formed by panels P and R, which are backed, respectively, bytriangularly shaped panels I and N, is then folded along the score line9 inwardly at ian angle of 90 from the plane of back sections D and E,respectively, whereby foil-t-o-foil contact between panels I and H fandpanels N `and L is made. Panel Q is then folded over at its outer edge:along score line 10 to `form a flap S, which is bounded by score lines10, 12 and .13 and edge 21 to form an angle of 180 with'the foil surfaceof panel Q. Panel Q is then folded at an angle of 90 'along score line 9to form :an angle of 90 with front panel B, whereby ap S is infoil-to-foil contact with panels P and R. Triangularly shaped panels Jand N are -heat sealed, respectively, to panels H rand L, panels K and Mare heat sealed, respectively, to portions of panels H and P andportions of panels R `and L and flap S is heat sealed to both panel Pand panel R. The resulting series of heat seals forms a Waterimpermeable end to t-he package just as the heat sealing of edge formedbetween flap F and edge area G is heat sealed to form a water imperviousside seam.

Panel H', which is bounded by score lines 3', 8 and 4 and edge 21 isfolded inwardly to form an .angle of With panel A falong score line 8.When panel H is folded inwardly, it holds triangularly shaped panel I',which is bounded by score lines 3 and 11 Iand edge 21 and triangularlyshaped panel K, which is bounded by score lines 4 and 12 and edge 21'outwardly so that they fold, respectively, .along score lines 1,1 and 13lat an angle of with, respectively, panel P which is bounded by s-corelines 2', 8 and 11' and edge 21 and panel Q' which is bounded by scorelines 8', 13', 10' and 12'. `8' and 6' yand edge 21', is `foldedinwardly, it holds triangulfarly shaped panel N', which is bounded byscore lines 6' `and 14' and edge 21', and triangularly shaped panel M',which is bounded by score lines 5' yand 13' and edge 21', outwardly sothat they fold, respectively, along score lines 14' -and .13' at ianangle of 180 with, respectively, panel R', which is bounded :by scorelines 8', 7' and 14' and edge 21' and panel Q', which is bounded byscore lines 8', 13', y10' fand 12'.

The ap formed by panels P' :and R' which are backed, respectively, bytriangularly shaped panels J' and N', is then folded along the scoreline 8' inwardly at an angle of 90 from the plane of back sections D'and E', respectively, whereby foil-to-foil contact between panels J'yand H' and panels N and L is mlade. Panel Q' is then folded over yatits louter edge along score line 10' to form a flap S', which is boundedby score lines 10', 12' and 13' and edge 21' to form an angle of 180with the foil surface of panel Q'. Panel Q' is then folded Iat an angleof 90 along score line 8 to form Ian angle of 90 with front panel B',whereby flap S' is in foil-tofoil contact with panels P' and R'.Triangularly shaped panels J' and N' may be heat sealed, respectively,to panels H' `and L', panels K' and M' are heat sealed, respectively, toportions of panels H' and P' and portions of panels R' and L' and flapS' may be heat sealed both to panel P' and panel R'. The resultingseries of heat seals, if employed, forms a water impermeable top end tothe package justas the heat sealing of edge formed between flap F' andedge area G' is heat sealed to form a water impervious side seam and thebottom of the package was heat sealed.

In the preferred form of this invention, however, panels H', J', K', L',M', P' and R' are folded, as indicated, but are not heat sealed, wherebythey form an adhesiveless barrier. In such event, each foil-to-foilcontact must be such that the length to width ratio of the opening is atleast 50. This is more fully illustrated in FIGS. 4 and 5.

By referring to FIG. 5, wherein portions of panels P' and Q' Iare shown,the relationship between the length, y, of the space between thefoil-to-foil surfaces and the width, x, of the space between thefoil-to-foil surfaces can readily been seen.

This ratio of yzx should lbe at least 50:1 and may be 100011 or evenhigher.

Were all the seams to be sealed, as described earlier, the ratio of )HxShould be `at least 10:1 'and may be 1000: l or even higher.

The invention is further illustrated by the following examples.

Example 1 A paperlaminatedtofoil wrapper for a single-componentcigarette pack was prepared by attaching aluminum foil (0.00035 inchthickness) coated continuously with polyvinyl acetate to 60-pound bondpaper with a conventional adhesive (casein). The resulting wrapper orlaminate was cut to the proper size to form a blank. The blank was thenscored along fold lines in a manner similar to that shown in FIG. 1 thatwould give foil-to-foil contact and insure that no edges of the paperwould be exposed to the outside when the blank is folded to form acigarette package.

The scored laminate was folded about the cigarettes in a manner similarto that described with regard to the drawing and each fold was heatsealed with a hand sealer heated to a temperature of about 275-300 F.,whereby the polyvinyl acetate coating was melted and served to seal thefolds together. The package was then enclosed with a cellophaneoverwrap. Similarly, another package was prepared with no cellophaneoverwrap. A standard soft pack (with standard folds which leave paperedges exposed) was used as a control.

When panel L', which is bounded by score lines The test packs andcontrols were conditioned for about 24 hours, then stored for six days,and at the end of the storage period, their 'water vapor transmissionvrates were determined. The cigarettes were analyzed either by the ovenmethod or the gas chromatographic method Ifor their initial moisturecontent. The cigarette packs were weighed and then placed in storagecabinets maintained under hot-Wet conditions F., 85% R.H.) land underhot-dry conditions (110 F., 15% R.H.). Ten samples of each of the twotest packs and the control were used for each storage condition. Thepacks were conditioned in the storage cabinets overnight (16 to 24hours) and then weighed to obtain their basic weights. At the end of sixdays, the packs were weighed to obtain the final weights. The cigarettesin the packs were analyzed for their final moisture content. The WVTRwas calculated as follows:

Rate of moisture loss:

Basic pack wt. (grams) final pack wt. (grams) (6 days) (20 cigts/packXav. tobacco wt./cigt., grams :percent/day Rate of moisture gain:

Final pack Wt. (grams) basic pack wt. (grams) X 100 (6 days) X (20cigts./pack av. tobacco wt./cigt., grams) =percent/day As can be seenfrom the data above, the wickless pack is 2-4 times more effective thanthe standard pack for preventing moisture migration. As a part of thesame test, actual changes in the moisture content were determined. Theoriginal moisture ocntent of the cigarettes in all three types of packwas 12.61%, calculated on an as-is basis (nondried). The packs werestored for six days in hot-dry and hot-wet 'conditions-110 F. and 15%relative humidity (RH.) and 90 F., 85% R.H. At the end of the storageperiod (termed seven-day storage because the day of conditioning wascounted), the percent of tobacco moisture change was calculated bysubtracting the percent moisture of the original tobacco from thepercent 4moisture after storage or vice versa. The results are givenbelow:

7-Day Storage Moisture Loss, Percent Moisture Gain, Percent Control,Cellophane 2.81 2. 54 Single Component, No Cellophane.- 1. 76 0. 44Single Component, Cellophane 0.51 0. 44

The heat sealed wickless package without a Icellophane overwrap was notas effective against moisture migration as the one with a cellophaneoverwrap but both of the wickless packs were significantly superior overthe control as water vapor barriers.

Example 2 was overwrapped with a printed paper label and a cellophaneoverwrap (a soft pack). Likewise, the 20-pound bond/foil was used as thecontainer of cigarettes to go inside a plastic pack.

Each of these packages and their controls were submitted to storageunder hot-wet and hot-dry conditions for six days and their water vaportransmission rates were calculated according to the formulae given inExample 1. The results are shown below:

Average Average Moisture Moisture Loss/Day, Gain/Day, Percent PercentFlip-Top Box/20 pound Bond/Foil Perforated/Cellophane 0. 384 0. 315Control (Standard Flip-Top Box) 0, 622 0. 458 Flip-Top Box/20 poundBond/Foil Non Perforated Cellophane 0.209 0. 262 Control (StandardFlip-Top Box) 0.622 0. 458 Soft Pack 45 pound Bond/Foil Cellophane. 0.141 0. 095 Control (Standard Soft Pack) 0.400 0. 386 Plastic Pack/20pound Bond/Foil/Cellophane 0. 128 0. 056 Control (PlasticPaek/Cellophane) 0.240 0. 185 Plastic Pack/20 pound Bond/Foil/NoCellophane 0. 161 0. 070 Control (Plastic Pack/Cellophane) 0.240 0.185

Example 3 Paper-laminated-to-foil wrappers which had been continuouslycoated with polyvinyl acetate were scored as described in Example l. Thetop fold was prepared to insure that the length of the fold Would be 50times the width of the gap when folding was completed. The blanks werethen folded into cases and all folds, except the top folds, were heatsealed. Cigarettes were inserted, and the top Was spot sealed to holdthe top fold close to the package but still leave a passageway throughwhich oxygen and carbon dioxide could diffuse. Similar packs werecompletely heat sealed and used as a control.

The original moisture content of the tobacco in the test and controlpacks was determined.

By using a rubber seal to completely obviate the possibility of aningress of atmosphere into the pack, a syringe was inserted into thetest and control packs, and the gases contained in the pack were pulledout. The original composition and amounts of these gases were determinedmass spectrophometrically. Packs which matched these packs were storedfor two months and again the gases in the test and control packs weredetermined. It was found that the test pack and control originallycontained oxygen and carbon dioxide in the same percentage in which theyoccur in the atmosphere. After the twomonth storage period, the oxyg-enand carbon dioxide content of the unsealed pack remained essentially thesame as the percentage in which they occur in atmosphere. In the sealedpack, the oxygen content had decreased and the carbon dioxide hadincreased. The moisture content of both packs was measured and found tobe virtually the same. The unsealed pack had breathed; that is, bydiffusion carbon dioxide had escaped from the pack and oxygen hadentered it. At the same time, the lack of a complete seal had littleeffect on moisture migration.

The two packs of cigarettes were submitted for subjective evaluation ofpack aroma. A difference in pack aroma was detected by the panel, and apreference for the pack aroma of the unsealed pack was expressed.

I claim:

1. A container for cigarettes formed from a substantially rectangularblank comprised of a plurality of layers, at least one of which is ahydrophylic layer and at least one of which is a water-impervious layer,said blank being folded to form a tubular lbody of substantiallyrectangular cross section having four side walls, two opposed ends ofthe blank being overlapped to form a seam extending longitudinally ofsaid body, said body having portions of opposed side walls adjacent bothends thereof folded inwardly substantially perpendicular to said sidewall providing end Walls for the container, each folded portion having asegment thereof overlapping a segment of at least one other foldedportion, the overlapping segments of the respective folded portionsforming seams in the corresponding container end walls, the overlappingsegments for-ming each end Wall seam and said longitudinal seamcomprising edges of said blank which have been infolded to provide awater impervious layer to water-impervious layer contact substantiallyalong the entire length of the corresponding seams, the overlappingsegments forming each seam providing passages through the container fromthe interior to the exterior thereof, each of said passages having alength which is at least 50 times greater than the spacing between theoverlapping segments forming said seams.

2. A container for cigarettes formed from a substantially rectangularblank comprised of a plurality of layers, at least one of which ishydrophylic layer and at least one of which is a water-impervious layer,said blank being folded to for-rn a tubular body of substantially-rectangular cross section having four side walls, two opposed ends ofthe blank being overlapped to form a seam extending longitudinally ofsaid body, said body having portions of opposed side walls adjacent bothends thereof folded inwardly substantially perpendicular to said sidewalls providing end walls for the container, each folded portion havinga segment thereof overlapping a segment of at least lone other foldedportion, the overlapping segments of the respective folded portionsforming seams in the corresponding container end walls, the overlappingsegments forming each end wall seam and said longitudinal seamcomprising edges of said blank which have been infolded to provide awater-impervious layer to water-impervious layer contact substantiallyalong the entire length of the corresponding seams, the overlappingsegments forming each seam providing passages through the container fromthe interior to the exterior thereof, each of said passages having alength which is at least 50 times greater than the spacing between theoverlapping segments forming said seams, said seams permitting gas flowtherethrough.

3. A container for cigarettes formed from a substantially rectangularblank comprised -of a plurality of layers, at least one of which is ahydrophylic layer and at least one of which is a water-impervious layer,said blank being folded to form a tubular body of substantiallyrectangular cross section having four side walls, two opposed ends ofthe blank being overlapped to form a seam exending longitudinally ofsaid body, said body having portions of opposed side walls adjacent bothends thereof folded inwardly substantially perpendicular to said sidewalls providing end walls for the container, each folded portion havinga segment thereof overlapping a segment of at least one other foldedportion, the overlapping segments of the respective folded portionsforming seams in the corresponding container end walls, the overlappingsegments forming each end wall seam and said longitudinal seamcomprising edges of said blank which have been infolded to provide awater-impervious layer to Water-impervious layer contact substantiallyalong the entire length of the corresponding seams, the overlappingsegments forming each seam providing passages through the container fromthe interior to the exterior thereof, the passage along a portion of atleast one seam having a length which is at least 5() times greater thanthe spacing between the overlapping segments forming said one seam, thepassages along the remaining seams having lengths at least 10 timesgreater than the spacing between the overlapping segments forming saidseams, said remaining seams being filled with adhesive.

4. A container for cigarettes formed from a substantially rectangularblank comprised of a plurality of layers, at least one of which is ahydrophylic layer and at least one of which is a water-impervious layer,said blank being folded to form a tubular body of substantiallyrectangular cross section having four side walls, two opposed ends ofthe blank being overlapped to form a seam extending longitudinally ofsaid body, said body having portions of -opposed side walls adjacentboth ends thereof folded inwardly substantially perpend-icular to saidside walls providing end walls for the container, each folded portionhaving a segment thereof overlapping a segment of at least one otherfolded portion7 the overlapping segments o-f the respective foldedportions forming seams in the corresponding container end walls, theoverlapping segments forming each end wall seam and said longitudinalseam comprising edges of said blank which have been info'lded to providea water-impervious layer to water-impervious layer contact substantiallyalong the entire length of the corresponding seams, the Overlappingsegments forming each seam providing passages, the passage along aportion of at least one seam having a length which is at least 50 timesgreater than the spacing between the overlapping segments forming saidone seam, the passages along the remaining seams having lengths at leastl` times greater than the spacing between the overlapping segmentsforming said seams, said remaining sea-ms being filled with adhesive,said one seam permitting gas flow therethrough.

5. A container for cigarettes formed fr-om a substantially rectangularblank comprised of a plurality of layers, at least one of which is alhydrophylic layer and at least one of which is a water-impreviouslayer, said blank being folded to form a tubular body of substantiallyrectangular cross section having four side walls, two opposed ends ofthe blank being overlapped to form a seam extendin-g longitudinally ofsaid body, said body having portions of opposed side walls adjacent bothends thereof folded inwardly substantially perpendicular to said sidewalls providing end walls for the container, each folded portion havinga segment thereof overlapping a segment of at least one other foldedportion, the overlapping segments of the respective folded portionsforming seams in the cor-responding container end walls, the overlappingsegments forming each kend wall seam and said longitudinal seamcomprising edges of said blank which have been infolded to provide awater-impervious layer to Water-imprevious layer Contact substantiallyalong the entire length of the corresponding seams, the overlappingsegments forming each seam providing passages through the container fromth-e interior to the exterior thereof,'

each of said passages having a length which is at least 100 timesgreater than the spacing between the overlapping segments forming saidseams.

6. In a container for cigarettes which is formed by folding around theycigarettes a substantially fiat blank comprised of a plurality oflayers, at least one of which is a hydrophylic layer and at least one ofwhich is a water-impervious layer with the blank having at least twoopposed ends which are overlapped, the overlapping segments of the blankforming a seam on the container, the improvement wherein the overlappingsegments comprise edge portions of the blank which have been infolded toprovide water-impervious layer t-o water-impervious layer contactsubstantially along the entire length of the seam, the overlappingsegments forming said seam providing a passage through the containerfrom the interior to the exterior thereof, said passage having a lengthwhich is at least times greater than the spacing between saidoverlapping segments.

References Cited by the Examiner UNITED STATES PATENTS 2,152,323 3/1939Moore 229-35 2,214,172 9/1940 Moore 229-35 2,252,462 8/1941 Howard229-87 JOSEPH R. LECLAIR, Primary Examiner.

DAVID M. BOCKENEK, Examiner.

1. A CONTAINER FOR CIGARETTES FORMED FROM A SUBSTANTIALLY RECTANGULARBLANK COMPRISED OF A PLURALITY OF LAYERS, AT LEAST ONE OF WHICH IS AHYDROPHYLIC LAYER AND AT LEAST ONE OF WHICH IS WATER-IMPERVIOUS LAYER,SAID BLANK BEING FOLDED TO FORM A TUBULAR BODY OF SUBSTANTIALLYRECTANGULAR CROSS SECTION HAVING FOUR SIDE WALLS, TWO OPPOSED ENDS OFTHE BLANK BEING OVERLAPPED TO FORM A SEAM EXTENDING LONGITUDINALLY OFSAID BODY, SAID BODY HAVING PORTIONS OF OPPOSED SIDE WALLS ADJACENT BOTHENDS THEREOF FOLDED INWARDLY SUBSTANTIALLY PERPENDICULAR TO SAID SIDEWALL PROVIDING END WALLS FOR THE CONTAINER, EACH FOLDED PORTION HAVING ASEGMENT THEREOF OVERLAPPING A SEGMENT OF AT LEAST ONE OTHER FOLDEDPORTION, THE OVERLAPPING SEGMENTS OF THE RESPECTIVE FOLDED PORTIONSFORMING SEAMS IN THE CORRESPONDING CONTAINER END WALLS, THE OVERLAPPINGSEGMENTS FORMING EACH END WALL SEAM AND SAID LONGITUDINAL SEAMCOMPRISING EDGES OF SAID BLANK WHICH HAVE